Swiss Cougar Busan Fast Charge 20W Power Bank - 20,000mAha fully charged 20,000mah power bank should charge an iphone 4 6 times from zero to full charge, before needing to be recharged itself. It should charge most modern android phones 3 4 times from zero to full charge. If youre using it for charging a tablet device, it should fully charge a large tablet once, or a small tablet twice. When used with a fast charging cable, this 20w power bank can charge your phone or tablet faster than a standard 10w power